Offset-preventing mechanism for printing-machines



I. TORNBERG OFFSET PREVENTING MECHANISM FOR PRINTING MACHINES,

7 .APPLICATION FILED SEPT.6, 1917- 1,374,253. PatentedApr- 12, 1921.

4 SHEET SSHEET I.

INVENTOR l. TORNBERG.

bFFSET PREVENTING MECHANISM FOR PRINTING MACHINES.

APPLICATION FILED SEPT. 6, 1917.

1,374,253. Y Patented Apr. 12,1921.

4 SHEETS-SHEET 2- I. TORNBERG. OFFSET PREVENTING MECHANISM FORPRINTING-MACHINES.

APPLICATION FILED SEPT. 6I I9I7.

9 v A E .a VM 4 TI rNN l. TORNBERG. v OFFSET PREVENTINGIMECHANISM FORPRINTING MACHINES.

APPLICATION FILED SEPT. 61 1917.

Patented Apr. 12, 1921.

4 SHEETSSHEET 4.

mvEm'oR A'rrws UNITED STATES" PATENT OFFICE.

rsrnon 'ronNBnne, or nw Y OItK, Y., 'ASSIGNOR r0 anon :AND 00., or NewYORK, N. Y., n conrona'rron or NEW YORK.

OFFSET-PREVENTING MECHANISM non rnrN'rme-mncnrmis.

Specification of Letters Patent.

PatentedvApri 12, 1921.

Application filed September 6, 1917. Serial No. 189,935.

,useful Improvements in Offset-Preventing Mechanism forPrinting-Machines, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.This invention relates to certain improvements in offset preventingmechanism for printing machines.

To, prevent offset, that is, an impression from the freshly printed sideof the web or sheet-and the second impression member, in

perfecting a web or sheell, therehave been commonly used a travelingofi'set web which, after being used, is rewound to be used over again,or a shifting offset web or tympan which is automatically periodicallyshifted so as to present a fresh surface against the freshly. printedside of the web every so many revolutions of the impression cylinder,this shifting tympan being wound upas it shifts in a suitable recessprovided within the cylinder Walls. Both of these ofi'set preventingmeans are open to objection, in that much time is lost in changing theposition of theofl'set rolls, resulting in frequent stoppage of themachine, and, if any damage should be done to the central portion of theroll, such as a wrinkle or tear, the entire roll is ruined and has to bethrown away, thus causing a considerable cost.' It has been proposed, toovercome these disadvantages,

' to employ ofiset sheets which shall be presented to the freshlyprinted side of the web between it and the second impression member. Inthe prior. constructions, however, for effecting this, the offset sheetwas presented to the freshly printed side of the web only after a numberof revolutions of the impression cylinder, and, consequently, after anumber of impressions. While this construction obviated some of thedifficulties referred to, there still was apt to be asmut caused by thefreshly printed side "of the web leaving offset on the oifsetsheet,which is offset or sm'utted' onto the succeeding portions of the web,owing to the fact that the sheet made a number of contact impressionswith the printed side of the web before 1t was changed. This resulted inbad printmg and is objectionable for this reason, particularly wherefine printing is desired.

It 1s one object of the present. invention toproduce a constructionwhereby 'ofl'set sheets may be fed from a pile or other suitable sourceof supply, so that a fresh sheet shall be presented between the printedweb or sheet and the impression cylinder at each lIIlPIBSSlOIl, theoffset sheet, after it has been printed aga nst, being returned to thepile and a fresh sheet substituted, a sufficient number of sheets beingused in rotation and a 'suflicient number of sheets being provided, sothat they will have time to sufficiently dry before they are againpresented to the printed web or sheet. v It 1s a further object of theinvention to provlde a feeding mechanism for feeding ofi'set sheets,which may be loaded while the work 1s going on, so that the feedingcanbe contmuous and no time lost and no stoppage of the'machine forchanging the feeding dev1ces 1s required. I

It 18 3. further object of the invention to produce an improvedmechanism'for feeding oflset sheets which may be so mounted in relationto the impression cylinder or other feeding mechanism as a whole may bemoved away from the impression cylinder so as "to allow readyaccess-thereto.

It is a further object of the ll'lVBIllZlOll'bO provlde such an offsetpreventing mechanism which may be employed with any type of perfectingprinting machine, whether the machine prints from a web, or from sheetssupplied thereto in any suitable manner, or from a web cut into sheetsprior to printing.

With these and other objects not specifically referred to in view, theinvention con sists in certain parts and combinations whichwill bespecifically described in connection with the accompanying drawings,

in which? Figure 1 is a diagrammatic side elevation of a rotary webperfecting press embodying the invention;

2 is a detailside view showing the run of the offset sheets through thefeeding "mechanism, the feeding mechanism being that shown-in ,Fig. 1;

Fig. 3 is a side elevation diagrammatically showing a'rotary printingmachine in which the sheets are cut from the web before being rinted andperfected, nd embodying the invention; Y

, F igpt is a, detailfside elevation showing one form of switchmechanism which may D M mechanismsmay be employed for effect ng beemployed to prevent a worn or dirty sheet from being returned totheimpression mechanism may vary wldely. in its specific cylinder;

Fig'. 5 is a sectional view, partly broken away,'showing an impressioncylinder and construction.

the arrangement for holdirig the blanket] and the grippers for holdingthe offset sheet in position, where the machine is used for, printing ona continuous web, the grippers being shown in closed position; I

' Fig. '6 1s a View similar to Fig. 5, the grip;

pers being shown in open position;

"Fig. 7 is a side View, partly in secti'onfof the construction shown inFigs. 5 and 6, and,

Fig. 8 is a view showing'the impression cylinder and arrangement wherethe machine shownin Fig. 8 isemployed for printing] I and perfectingsheets cutfrom a web.

Referring now to the' drawings and first to Figs I, 2 and): to 7,inclusive, the invention is shown as'embodied in a rotary ma-.

chine in which a continuous web is printed and perfected and then led toother mechanisms in'whi'ch it is cut or folded. ,Thevaor suitable construction. Suitably supported.

in the frames is a web roll W from which the w p grippers "l l'which arecarried in blocks 15 web W. is led over the usual guiderolls 2 i.throughthe first printing couple which includes a form cylinder 3 andan impression cylinder l: The particular machine illustrated in Fig.1is'a'rrangedto print in'one color onone side, of the web: and to perfecta web in two colors. After the web is rint-v ed in theprinting couple'3,4:, it is per ecte'd by form cylinders 5, 6 which cobperate' with I alarge impression cylinder 7,- the web, after it has been perfected,being led from the J-machine over the usual guide roll 8. Inkingmechanisms 9 of any usual type are provided :In machines embodying theinvention, there will be provided a mechanism for feed ing-offsetsheetsibetween the freshly printed side of the, web andtheimpressioncylinder of the second all perfecting printing couple, andin machines embodying the invention in its besii form these offsetsheets will be'fed. cohtinupuslj and by mechanism which can be loaddwhile the machine'is. worki'n'g,"so

that the operation of feeding the sheets will 'be continuous, thusobviating a y necessity for stopping the machine'to effect the'chajngeof the sheets.- Furthermore; these "oifset sheets will, be "ofdimensions corresponding.

with the length of the impression made by the form cylinder and one ofthesebfis'et sheets will be fed between the freshly printed web and theimpression cylinder of the perfecting couple at'each operation of thepers.

impression cylinder, a sufficient number of thisffeeding of theofisetsheets and-such In theparticular machine illustrated, however, there isprovided a 'feedingf'mechanism in which the sheets 'marked S (see Fig.2) .are fed into the machine from a 'pile'whichmay be placed on a thisfeedin being efiected by means of the usual combing roll 11 which actsto comb or .fan'out the sheets as is usual in sheet feeders,

a presser foot 12 being "provided as. usual a common one and 'of itselfforms no part of the invention.

over suitable feeding-in rolls 13 and are taken by suitable. sheettakingadevicescar ri'ed by the second impression cylinder. The sheettaking devices ma'ybeof any suitable character. In the particularconstruction illustrated, these sheet taking devices arev mountedjfo n ashaft 16 suitably positioned within the cylinder, this shaft beingcarriedv are fedfrom theifeedei" ifeed table 10 ,which is suitablylocated closely; adjacent the second impression cyl-. Jinder 7.The'sheets are fed from this table 'so that the undersheet ofthe pile isfirst de- A 7 livered or fed to the-impression cylinder,

onrock arms 17. which are operated in any nsual orqdesired' manner foreifecting' the opening" andclosing movement of the grip- The grippersl4, operate through a slot '14 formed in the cylindcrwall and in,

the bestconstructions these grippers will be [formed and will beoperatedso that when in" their closed position they will be entirely'below thefsurface of the .cylinder as shown in Fig.- 5, so as not toiriterferewith the web passing around the cylinderi These gripperscoeperate with suitable abutments 15 to 'hold the sheet firmly in'position on the cylindenblanket. Where. as in the-machine Iillustrated, the second impression'cyli-nder is twice the diameter ofthe two 'form cylinders with;which itcotiperates, this cylinder will, ass'hoWn in'Fig, 1,-be provided -with we sets of oifset sheettakinggrippers which identical in construction and operation, "the twosets'of grippersbeing provided so that the freshv sheet may be fed foreach im 'pressiong It may bestated that the i'mpression cylinder isas'usual provided with any impression blanket indicated at' l8 (Figs. 5-'and -'.6),' the "ends of which extend into the.

cylinder and which may be adjusted by the usual blanket rolls 19 locatedwithinthecy1 inder walls. a

After the oifset sheet has been passed "with. the web throu h themachine, it is delivered from the cy inder back onto the top of the pileon the feed table 10 over suitinvention in its best form means willbeprovided for pushing. or lifting the end of the offset sheet from thecylinder to insure v the sheet passing to the guide before referred to,over which the sheet is delivered to the table. While these means mayvary; in the particular construction illustrated there are provided aseries of pushing pins 21 carried on slides 22 mounted on blocks 23suitably secured within the cylinder, the slides 22 being operated byrock arms 25, 25 on a shaft 26,- one of the arms, as 25, taking into aslot in the lower end of the slides, and the other arm 25- beingoperated from a cam roll 27 secured thereto and operated from a cam 28suitably secured to the frame of the machine, this cam being indicatedin dotted lines in. Fig. 6. These pushers, as shown in Fig. 6, whenelevated, act to lift up or strip the end of the sheet S from thecylinder and assure the sheet passingonto the guide 20.

In machines embodying the invention in its best form, devices will beprovided whereby a worn or too badly soiled sheet may be prevented 'fromagain passing through the machine from the feeder, such worn or soiledsheet being removed as it is delivered to the top of the pile by theguide. Various devices may be employed for such purpose, but aconvenient one is that illustrated in Fig. 4 inwhich there is shown areceptacle 30 mounted in any suitable manner adjacent the feedingmechanism. This receptacle has an open end and at the open 'end isprovided a switch 31 pivotally mounted on a stud 32, the switch beingoperated by hand lever 33. When a worn or badly soiled sheet comesthrough, the operator simply throws this'switch into the position shownin Fig. .4, which causes such sheet to be delivered to the receptacle30,

- instead of again passing around the combing roll '11 and into themachine.

For convenience 1n access to the second impression cylinder, in the bestconstruefrom the second impression cylinder by means of a pinion 36cooperating with racks 37, this pinion being operated by any suitabletool. v Y

The construction so far described provides for the feeding of the offsetsheets at eachimpression to printing machines in which a continuous webis 'printed. In Figs. 3 .and 8 is shown a construction in which the .webis cut into sheets after be-- ing printed upon. Such construction, inaddition to the mechanisms hereinbefore described, includes a pair ofcutting cylinders 38, 39, sheet feeding mechanism 40, and ad ditionalsheet taking devices which are shown as grippers 41, are provided, onthe 'second impression cylinder for holding the cut sheets thereon. Whenthe machine is, as shown in Flgs. 3 and 8, arranged to print and perfectsheets out prior to the printing,

the usual taking cylinder 42 and delivery cylinders 43, 44:: may beprovided. .The

- mechanism for feeding the offset sheet to the second impressioncylinder in this type of machine will, however, be similar to thatheretofore described and consequently need not be described again.

While a simple and eflicient construction has been illustrated anddescribed for effecting the objects of the invention and suchconstruction has been shown as embodied in two types of perfectingprinting machines, it will'be understood that various feeding mechanismsmay be employed for continuously feeding offset sheets in rotationthrough the machine and that such feeding mechanism may be employed withother types of perfecting machines than those shown and described andthat the invention is not to be limited to the precise type ofperfecting machine or feeding mechanism shown.

What is claimed is V 1. In a printing machine, the combination with aprinting eouple, of'a pile of offset sheets, and means for feedingoffset sheets continuously thereto from the bottom of the pile, one suchsheet being fed for each im-- pression operation of the impressionmember of the couple.

2: In a printing machine, the. combination with an impression cylinder,of means for feeding one of a plurality of superposed offset sheetsthereto inrotation, onesuch sheet being fed for each impressionoperation of the cylinder.

3. In a printing machine, the combination with an impression cylinder,of means for continuously feeding oneof a plurality of superposed offsetsheets thereto in rotation, one such sheet being fed for each impressionoperation of the cylinder.

4. In aprinting machine, the combination with an impression cylinder, ofmeans for supporting a pile of ofi'set sheets, means for feeding thesheets successively to the impression cylinder, one sheet being fed foreach impression'operation thereof, and means for returning-the sheets tothe pile.

5. In a printing machine, thejcombination with an impression. cylinder,of 'means for tem of the pile to thecylindenand devicessupporting a pileof offset sheets, means for feeding thefsheets successively from thebotfor -returning 'the sheet to the'top of the'pile.

"6. In a printing machine, the combination with an Impression cylinder,of means for 1 supportin 'a pile of offset sheets, means for -feedingmeans may have a bodily movement to and from the cylinder, a clear spacebeing left after .such movement so that 'free access may be had .to thecylinder.

' 8. In a printing machine, the combination with an'im'pressioncylinder, of a support for. a-pile of offset sheets, a feeding mechaandmeans for sliding the frame to and from r for feeding thesheetssuccessively to the cylinder, 9. frame in which the pile supportand the feeding mechanism is mounted,

I the impression cylinder, 2, clear space-being maybe had tothe-cylinder.

left after such movement so thatlfree access 9; In" a printing machine,the combination with an impression cylinder, of-meansfor supporting apile of sheets, of means for successively feeding'the sheets to .thecylinder,-means for delive'ringlthe sheets from the cylinder to the topof the pile; and a switchfor switching'a sheet away from the .tion' witha printing couple and means for pile.

10. In a printing machine, the-combinafmy hand.

supporting a pile of offset sheets, of means for feeding the sheetssuccessively to the. impressionmemberof the couple, one sheet being fedfor. each impression operation thereof,-and means for returning thesheets to thepile.

11. In a printing machine, the combine tion with an impression cylinder,of means for feeding the sheets successively from the: bottom of thepile to "the impression cylin operation thereof, and means for returningthe sheets to the pile.

for supporting a pile ofbfi'set sheets, means der, one sheet being fedfor each impression 12. In a printing machinefthe .conltbina I tion witha printing couple; of means for supporting" a pile of ofi'setsheets,means for Y successively feeding the sheets to the mipression member ofthe couple, ineans forl.

, delivering the sheets to the pile,1 and; devices for preventing thereturn of a sheet to the pile. i i

13. tion with a printingcouple, of means forsupporting a pile ofoffsets-sheets, means for successively feeding the sheets to theimbottom of the pile, means fo'r returning the lsheets to the top of thepile, and devices for preventing-the return ofa sheet to the pile.

14. In a-printing machine,.the combina- ;tion of an impression imember,means for;

feeding offset sheets thereto from a pile and -means for returning thesheets to the same pile from which they were-fed.

' 15. In 'aprinting machine, the c01nbina- In a printingmachine, theconibina-v pression member of the coupleffrom the tion .of an impressionmember, means'fOr feeding a fresh pfi's'et sheet thereto from a pile ateach-operation of. the member, and v means for returning the sheets tothe *sam pilefrom which they were fed. v

In testimony whereof, I'ha ve hereunto'set IsIDoR ToRNBnne.

